The Mouse Auditory Testing Core (MATC) Facility was established in July 2011. The MATC assists the Principle Investigators of the NIDCD and their collaborators with auditory testing in mice. Dr. Fitzgerald can provide consultation on auditory testing during all phases of a project and can provide training in auditory testing techniques for investigators. The facility also assists with protocols that require noise exposure. Two physiological measures of auditory function are employed at the MATC: auditory brainstem response (ABR) testing and distortion-product otoacoustic emissions (DPOAEs). The ABR is an evoked potential that can be used to estimate hearing thresholds. The ABR is measured by placing electrodes on the scalp and recording the potentials generated by the auditory nervous system when a sound is repeatedly presented to the ear. DPOAEs are soft sounds that are recorded in the ear canal and can be used to screen for hearing loss or to evaluate inner ear (cochlear) function. The presence of DPOAEs indicates normal function of outer hair cells in the inner ear. DPOAEs are measured by placing a small probe containing two speakers and a microphone in the opening of the ear canal. Two tones are played simultaneously to the ear and the DPOAEs produced by the ear are recorded by the microphone. In the second year of operation, 14 investigators from the NIDCD have been trained in ABR and DPOAE test techniques and interpretation. Dr. Fitzgerald has collaborated on 20 projects conducted in eight labs within the NIDCD and has one paper in press. Dr. Fitzgerald assisted with planning auditory test protocols, collection of DPOAE and ABR data, and analysis of auditory test data for the following projects. In many cases, the goal was to establish the auditory phenotype for a particular mutant mouse strain. Additional contributions are noted where applicable. Chadwick Lab: Dr. Arun Palghat Udayashankar (Visiting Post-Doctoral Fellow) and Cecilia Johannson (Ph.D. Candidate, NIH-Karolinska Institute) received training in DPOAE and ABR testing and interpretation. Dr. Fitzgerald collaborated on Cecilia Johannson's project investigating Tectb mutant mice. Chien Lab: Kevin Isgrig (Biologist) is receiving training in DPOAE and ABR testing and interpretation. Dr. Fitzgerald is collaborating on an ongoing project investigating the use of gene therapy to remediate hearing loss. Dr. Fitzgerald assisted with preparation of a poster on the project presented at the Midwinter Meeting of the Association for Research in Otolaryngology in February, 2013. Cunningham Lab: Dr. Soymen Roy (Visiting Post-Doctoral Fellow) and Andrew Breglio (Medical Research Scholar) received training in DPOAE and ABR testing and interpretation. Dr. Fitzgerald collaborated on two related projects examining the use of moderate noise exposure to reduce the hearing loss caused by the ototoxic drugs kanamicin and cisplatin. Dr. Fitzgerald also assisted with calibration of noise stimuli and with preparation of the manuscript (in press) for these projects. Friedman Lab: Stacey Cole (Post-Bac IRTA), Eva Morozko (Post-Bac IRTA), Dr. Julie Schultz (Biologist), and Elizabeth Wilson (Veterinary Technologist III) received training in DPOAE and ABR testing and interpretation. Dr. Fitzgerald collaborated on seven projects in the Friedman lab, including an investigation of the auditory phenotype of GM1714 mutant mice for Dr. Robert Morell (Staff Scientist), a project on Myosin15 mutant mice for Dr. Jonathan Bird (Post-Doctoral Fellow), and a project examining the auditory phenotype in Hgf mutant mice for Dr. Schultz. Dr. Fitzgerald assisted Eva Morozko and Dr. Inna Belyantseva (Staff Scientist) on four projects: two investigating Tprn mutant mice, one on ILDR1 mutant mice and one on Triobp mutant mice. Griffith Lab: The MATC provided training in DPOAE and ABR testing and interpretation for two Visiting Post-Doctoral Fellows: Hiroshi Nakanishi and Ayako Nishio. Dr. Fitzgerald collaborated with Dr. Nakanishi on his project examining Tmc1 mutant mice and is collaborating with Dr. Nishio on two projects investigating Slc26A4 mutant mice. Kachar Lab: The MATC provided training in DPOAE and ABR testing for Dr. Taro Fujikawa (Visiting Post-Doctoral Fellow). Dr. Fitzgerald collaborated on Dr. Fujikawa's project on the kainate receptors of the outer hair cells and their afferent terminals. Dr. Fitzgerald was a co-author on a poster on this project presented at the Midwinter Meeting of the Association for Research in Otolaryngology in February, 2013, and will assist with manuscript preparation. Kelley Lab: Drs. Helen May-Simera and Thomas Coate (Post-Doctoral Fellows) received training in DPOAE and ABR testing and interpretation at the MATC. Dr. Fitzgerald collaborated on four projects in the Kelley lab: Dr. May-Simera's project on Bbs8 mutant mice and Dr. Coate's projects on PPARG, the axon guidance factor EphA7, and Nrp mutant mice. Wu Lab: The MATC provided training in DPOAE and ABR testing and interpretation for Yanhan Huang (Technical IRTA). Dr. Fitzgerald collaborated on a project investigating Dreher mice. Assembly of a new system that will allow investigators to evaluate vestibular/balance function using vestibular sensory evoked potentials (VsEPs) began in the summer of 2013 and is in progress. VsEPs are recorded by placing electrodes on the scalp, similar to an ABR, and recording the electrical potentials generated by the vestibular nervous system in response to linear movements of the head.